Electrotechnics N5

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Electrotechnics N5

This document includes important informa on about the revised curriculum for Electrotechnics N5, scheduled for implementa on in 2021. Contact jayshil.bhula@macmillaneduca on.co.za to request a sample copy of the TVET First approved textbook or visit our website at www.macmillaneduca on.co.za. For best results, use TVET First Electrotechnics N5!

Changes to the curriculum for 2021:

• Modules 7 to 10 of the previous curriculum have been removed. • The revised curriculum has been broken down into weighted modules with learning content and detailed, numbered Learning Outcomes. • Some of the modules have been reordered.

Modules and weigh ngs:

The new curriculum has been broken down into modules with weigh ngs as follows:

New curriculum (2021):

Module 1 DC machines 20%

Module 2 AC theory 20%

Module 3 Transformers 20%

Module 4 Measurement of power in AC circuits 10%

Module 5 AC machines 20%

Module 6 Genera on and supply of AC power 10%

Summary of changes:

Overview/highlights:

• The curriculum is largely unchanged. • Modules have been weighted and reordered slightly. • Welding machines and methods of reversing are no longer covered in the DC machines module. • Welding machines, cooling methods and tap-changing are no longer covered in the transformer module. • Range changing – shunt resistance and transformers are no longer covered in the module on measuring instruments. • Speed control by pole changing, reversal and circle diagrams are no longer covered under induc on motors in N5.

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• Switchgear and protec ve devices (old Module 7) have been removed completely. • Sta c control (old Module 8) has been removed completely. • Installa on, care, opera on, maintenance, supervision and inspec on of transformers, cables, switchgear and protec ve devices (old Module 9) have been removed completely. • Materials used for the design of electrical equipment and types of dielectric (old Module 10) have been removed completely.

Changes in more detail:

Module 1 Weight 20%

Module 2

Weight 20%

Module 3

Weight 20%

Changes

DC machines Learning content remaining on:

• DC motor characteris cs and applica ons • Calcula ons of back emf (KVL and emf equa on) and torque induced • Armature reac on (defi ne, diagrams, calcula ons) • Commuta on (defi ne, diagrams, calcula ons, methods to reduce) • Speed control of DC motors (diagrams and calcula ons) • Resistance star ng of DC motors (diagrams and calcula ons) • Characteris cs of DC generators and calcula ons to obtain level compounding

Content removed:

• Methods of reversing • Welding machines

AC theory Learning content remaining on:

• Genera on of an alterna ng EMF, AC waveforms and alterna ng quan es (defi ni ons and calcula ons) including mid-ordinate rule • RLC circuits • Power in AC circuits • Three phase balanced and unbalanced loads (star only for unbalanced)

Transformers Learning content remaining on:

• Opera on of a single phase transformer including useful and leakage fl ux • Circuit and vector diagrams on no-load and full-load plus calcula ons • Equivalent circuit ignoring voltage drops • Equivalent resistance, reactance and impedance • Voltage regula ons (leading and lagging power factor)

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Module 4

Weight 10%

Module 5

Weight 20%

Module 6

Weight 10%

Changes

• Losses and open and short-circuit tests • Three phase transformers (diagrams and calcula ons) • Parallel opera on of transformers (requirements and calcula ons)

Content removed:

• Welding machines • Cooling methods are no longer covered (covered in N4) • Tap-changing on and off load

Measurement of power in AC circuits (This was previously Module 6) Learning content remaining on:

• Measuring power in balanced and unbalanced systems with wa meters

Content removed:

• Range changing – shunt resistance is no longer covered in N5 • Transformers are no longer covered in this module

AC machines (This was previously Module 4) Learning content remaining on:

• Emf equa on of an alternator • Parallel opera on of alternators (diagrams and calcula ons) • Opera on, star ng, characteris cs and hun ng of synchronous motors • Three phase induc on motors – opera on, slip, energy fl ow (losses) and torque (including calcula ons), current speed rela onship

Content removed:

• Speed control by pole changing (induc on motor) • Reversal (induc on motor) • Circle diagrams are only covered in N6

Genera on and supply of AC power (This was previously Module 5) Learning content remaining on:

• Resistance, inductance and capacitance of overhead transmission lines • Voltage regula ons and effi ciency of short transmission lines

TVET First author:

Sunil Chuturgoon